Improvement in breech-loading ordnance



c. GRIMSHAW.

Breech-Loading Ordnance,

Patented Oct. 29, 18.61.

Wm El k i Unite PATENT Orricn.

CHRISTOPHER GRIMSHAVV, OF MILWAUKEE, \VISCONSIN.

To all whom it may concern.- Be it known that I, CHRISTOPHER GRIM- sHAW, of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented a new and useful Improvement in Breech- Loading Cannon; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, making part of this specification, in which Figure l is a plan of a cannon with my improvement. Fig. 2 is a horizontal axial section of the same. Fig. 3 is an elevationof the rear end thereof.

Similar letters of reference indicate corresponding parts in the several figures.

My invention relates to the class of breechloading cannon which has a bore extending completely through, and a movable plug inserted transversely of the latter; and the improvement consists in a novel construction of parts, adapting the plug to be continued tight.

and effective when the piece has become distorted by use. I

To enable others skilled in the art to make and use my invention, I will proceed to de scribe its construction and operation.

A is the bore, extending completely through from end to end, and rifled, with the exception of a chamber at the breech, which receives the cartridge in loading. The body of the gun is enlarged at the breech, and provided on each side with a cylindrical projection, 13, pierced with a conical aperture, ex tending completely through the gun transversely to its bore, and of larger diameter than the latter.

C represents a conical plug, ground to fit the transverse aperture, so as to form a gastight joint. \Vhen in position, the plug 0 is secured bya key, 0.

To load the gun, the plug 0 is withdrawn and the cartridge inserted from the rear. The plug being then replaced, the piece is ready to fire. compensate for the cutting away of metal to The enlargement and form of the breech Specification forming part of Letters Patent No. 33,582., dated October 29, 1861.

admit the plug, and thus secure the requisite degree of strength.

The round plug possesses many important advantages over a square one. It-is much stronger in proportion to its size, and requires aproportionatelysmaller aperture in the gun to receive it. As the gun expands by use, and the aperture becomes elongated and enlarged by this action and by the force exerted upon the plug by the explosion, the round plug may readily be kept tight by grinding, whereas to fit a square plug to'its aperture requires a skilled mechanic.

For ships guns the projections B afford convenient means of attachment for stay-ropes, as shown in Fig. 1, to resist the recoil of the gun.

For the heaviest ordnance a lever or other mechanical appliance may be employed to insert and Withdraw the plug.

The gun, being bored completely through, is adapted for the use of telescopic lenses for sighting through the barrel. Such lenses are shown in Fig. 2 in positions occupied when the piece is discharged.

I am aware that a perforated faucet breechplug .has been used for admitting the charge through it. This, therefore, I do not claim;

CHRISTOPHER GRIMSHAV.

Witnesses:

EDM. F. B OWN, L. W. BENDIE. 

